Navigating deeply nested arrays while parsing JSON in JavaScript

Question

Navigating deeply nested arrays while parsing JSON in JavaScript

I'm currently working on parsing JSON data with JavaScript, but I've hit a roadblock when trying to access the value that is part of the first PWER object (the value changes and I simply want to display it on the webpage). Additionally, the '1452520496000' portion also changes based on time. As someone new to JavaScript and JSON, I find the examples I have come across during my research to be relatively straightforward compared to this particular case where I need to access the PWER in "cid": "PWER".

Below is an excerpt of the JSON output received from the API:

[
{"cid":"PWER",
 "data":[{"1452520496000":568}],  
 "sid":"144",
 "units":"kWm",
 "age":5
 },

{"cid":"MOTN",
 "data":[{"1452520489000":0}],
 "sid":"910",
 "units":"S",
 "age":12
 },

{"cid":"LGHT",
 "data":[{"1452520489000":19.09}],
 "sid":"910",
 "units":"L",
 "age":12}
 ]

In order to tackle this challenge, I have adopted code snippets from the example provided here as a foundation for the HTTP GET request while I figure out how to parse the JSON data efficiently. Here's what I have managed to put together so far:

<div id="main"></div>

<script>
var xmlhttp = new XMLHttpRequest();
var url = "URLGoesHere";

xmlhttp.onreadystatechange=function() {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        myFunction(xmlhttp.responseText);
    }
}
xmlhttp.open("GET", url, true);
xmlhttp.send();

function myFunction(response) {
    var arr = JSON.parse(response);

    var out = arr[0].data[0];

    document.getElementById("main").innerHTML = out;
}
</script>

The problem I am facing is that instead of displaying the desired result, my page shows [object Object].

To troubleshoot, I've been using the console:

console.log(arr[0]);

Object {cid: "PWER", data: Array1, sid: "144", units: "kWm", age: 5}

This confirms that the API token is successfully accessed and data is being retrieved.

In order to dig deeper into the retrieved data, I check the contents of 'Array1' within 'data':

console.log(arr[0].data);

[Object]
0: Object
length: 1
__ proto __: Array[0]

My next step involves trying to access the object at index 0:

console.log(arr[0].data[0]);

Object {1452520496000: 568}

The desired value of 568 is present, however, I am unable to access it due to the ever-changing nature of the '1452520496000' parameter. What would be the most effective approach to accessing this value?

javascript json api

Answer 1

Answer №1

To retrieve the specific key you need, you can utilize the Object.keys(object) method.

var information = arr[0].data[0];
var keysList = Object.keys(information);
console.log(keysList[0], information[keysList[0]]);

Answer 2

To retrieve the specific key you need, you can utilize the Object.keys(object) method.

var information = arr[0].data[0];
var keysList = Object.keys(information);
console.log(keysList[0], information[keysList[0]]);

Answer 3

Answer №2

let firstData = arr[0].data[0];

console.log(firstData[ Object.keys( firstData )[ 0 ] ] );

Retrieve all the keys from firstData by using Object.keys(), save them in an array, and then access the key at the first index.

Answer 4

let firstData = arr[0].data[0];

console.log(firstData[ Object.keys( firstData )[ 0 ] ] );

Retrieve all the keys from firstData by using Object.keys(), save them in an array, and then access the key at the first index.

Answer 5

Answer №3

JSON operates based on the key-value pair concept. The object currently being utilized does not adhere to the JSON format.

"information":[{"1547283021000":673}],

You have the option to utilize the above data in two different formats:

Include both values within an array
```
"information":["1547283021000", "673"],
```

Utilize specific keys

"information":{"key1":"1547283021000", "key2":"673"},

If you wish to stick with the same format, here is a method I discovered to parse your JSON

var d = 'your json';
var parsedObjects = $.parseJSON(JSON.stringify(d));

Convert the JSON into a string and then proceed with parsing it.

Answer 6

JSON operates based on the key-value pair concept. The object currently being utilized does not adhere to the JSON format.

"information":[{"1547283021000":673}],

You have the option to utilize the above data in two different formats:

Include both values within an array
```
"information":["1547283021000", "673"],
```

Utilize specific keys

"information":{"key1":"1547283021000", "key2":"673"},

If you wish to stick with the same format, here is a method I discovered to parse your JSON

var d = 'your json';
var parsedObjects = $.parseJSON(JSON.stringify(d));

Convert the JSON into a string and then proceed with parsing it.

Answer 7

Answer №4

amy2874 provided an excellent solution. Another option is to iterate through the POJO in 'data' using a simple loop. Here's one way to do it with a basic for loop (but there are more efficient looping methods available):

var data = arr[0].data[0];
var result;
for (var property in data) {
    result = data[property];
}

Keep in mind that if there are additional keys within the 'data' object, you'll need to include error handling before assigning a value to 'result'. For example, if the object looks like this:

{
    ...
    data: [{ "foo": "someval", "1452520496000": 568, "bar": "someotherval" }]

In this case, you should implement some validation logic inside the loop to ensure you're targeting the correct key. It's also advisable to break out of the loop as soon as you've found the desired key for performance reasons.

Answer 8

amy2874 provided an excellent solution. Another option is to iterate through the POJO in 'data' using a simple loop. Here's one way to do it with a basic for loop (but there are more efficient looping methods available):

var data = arr[0].data[0];
var result;
for (var property in data) {
    result = data[property];
}

Keep in mind that if there are additional keys within the 'data' object, you'll need to include error handling before assigning a value to 'result'. For example, if the object looks like this:

{
    ...
    data: [{ "foo": "someval", "1452520496000": 568, "bar": "someotherval" }]

In this case, you should implement some validation logic inside the loop to ensure you're targeting the correct key. It's also advisable to break out of the loop as soon as you've found the desired key for performance reasons.

Navigating deeply nested arrays while parsing JSON in JavaScript

Answer №1

Answer №2

Answer №3

Answer №4

Similar questions

Utilize JavaScript to parse JSON containing multiple object settings

When package.json is imported, files are not compressed

What improvements can I implement to enhance the clarity and functionality of this form handler?

Eliminating redundant files in the upload section

Why is my React app opening in Google Chrome instead of the API?

What is the best approach for transforming a string that resembles a dictionary into an actual dictionary?

Merge array and object destructuring techniques

Exploring the functionality of OpenLayers 5: Removing a map layer with a checkbox

I'm puzzled by the error I'm encountering with my PHP cURL request to the GitHub API, especially considering it functions perfectly in Postman. What could

AngularJS UI-Router: Utilizing Optional Parameters

Adding an item to an array in Angular 2 using JavaScript!

Guide on clearing an email input field in JavaScript after it has been filled with white spaces, when setting the value to an empty string ("") does not produce the desired result

What is the best way to save a collection of image and video files using JavaScript?

Numerous JavaScript functions seamlessly integrated into HTML

Looking to iterate through a dataframe and transform each row into a JSON object?

I am unable to comprehend the function definition

Is it possible to trigger a Bootstrap 5.2 Popover within an "if" statement?

Error message "Webpack is encountering an issue stating you might require a suitable loader" appearing during React development using TypeScript

How can I show name and value pairs as columns in SQL Server?

Fixing Android Volley's onClick retry functionality issue